//! The pending queue (`sync.pending`): the local changes the server does not
//! have yet, from a scan of the vault against `SyncState.bases`.

mod common;

use common::{TempVault, seed, temp_vault};
use notescraft_engine::sync::queue::{ChangeKind, MAX_QUEUE, PendingChange, pending_changes};
use notescraft_engine::{Registry, Session, SyncState, register_core};
use notescraft_sync::Base;
use notescraft_vault::Vault;
use serde_json::{Value, json};

/// A vault in a fresh folder.
fn vault(name: &str) -> (Vault, TempVault) {
    let kept = temp_vault(name);
    let opened = Vault::open(kept.path()).expect("open the temp vault");
    (opened, kept)
}

/// Records the state the last sync would have left: every pair of
/// `(path, content)` becomes a base at the hash of its content.
fn recorded(vault: &Vault, files: &[(&str, &str)]) {
    let mut state = SyncState::default();
    for (path, content) in files {
        state.bases.insert((*path).to_owned(), Base { hash: notescraft_sync::hash_hex(content.as_bytes()), seq: 1 });
    }
    state.save(vault).expect("save the state");
}

/// A vault where a note is new, an other edited, a third deleted (its base
/// stays recorded) and a fourth untouched.
fn mixed(name: &str) -> (Vault, TempVault) {
    let (vault, kept) = vault(name);
    seed(kept.path(), &[("new.md", "added here"), ("edited.md", "changed now"), ("same.md", "as synced")]);
    recorded(&vault, &[("edited.md", "was like this"), ("gone.md", "deleted"), ("same.md", "as synced")]);
    let _ = std::fs::remove_file(kept.path().join("gone.md"));
    (vault, kept)
}

/// The paths of the answer, as the tests read them.
fn paths(changes: &[PendingChange]) -> Vec<(&str, ChangeKind)> {
    changes.iter().map(|change| (change.path.as_str(), change.kind)).collect()
}

#[test]
fn the_kinds_follow_the_bases() {
    let (vault, _kept) = mixed("kinds");
    let changes = pending_changes(&vault).expect("pending");
    assert_eq!(paths(&changes), [("edited.md", ChangeKind::Edited), ("gone.md", ChangeKind::Deleted), ("new.md", ChangeKind::Added)], "sorted by path");
    assert_eq!(changes.iter().find(|change| change.path == "new.md").map(|change| change.size), Some("added here".len() as u64), "the size of the file now");
    assert_eq!(changes.iter().find(|change| change.path == "gone.md").map(|change| change.size), Some(0), "a deleted file has no size");
}

#[test]
fn excluded_folders_are_never_listed() {
    let (vault, kept) = vault("excluded");
    seed(kept.path(), &[("note.md", "real")]);
    std::fs::create_dir_all(kept.path().join(".obsidian")).expect("obsidian");
    std::fs::write(kept.path().join(".obsidian/workspace.json"), "state").expect("obsidian");
    std::fs::create_dir_all(kept.path().join(".notescraft/sync")).expect("notescraft");
    std::fs::write(kept.path().join(".notescraft/sync/kept.json"), "state").expect("notescraft");
    let changes = pending_changes(&vault).expect("pending");
    assert_eq!(paths(&changes), [("note.md", ChangeKind::Added)], "only the note travels");
}

#[test]
fn the_queue_caps_at_500_entries_in_path_order() {
    let (vault, kept) = vault("cap");
    let names: Vec<(String, String)> = (0..600).map(|index| (format!("note-{index:03}.md"), format!("#{index}\n"))).collect();
    seed(kept.path(), &names.iter().map(|(path, text)| (path.as_str(), text.as_str())).collect::<Vec<_>>()[..]);
    let changes = pending_changes(&vault).expect("pending");
    assert_eq!(changes.len(), MAX_QUEUE);
    assert_eq!(changes.first().map(|change| change.path.as_str()), Some("note-000.md"));
    assert_eq!(changes.last().map(|change| change.path.as_str()), Some("note-499.md"));
    let mut sorted = changes.clone();
    sorted.sort_by(|left, right| left.path.cmp(&right.path));
    assert_eq!(changes, sorted, "sorted by path");
}

#[test]
#[cfg(unix)]
fn an_unreadable_file_is_skipped() {
    use std::os::unix::fs::PermissionsExt;
    let (vault, kept) = vault("unreadable");
    seed(kept.path(), &[("good.md", "readable"), ("locked.md", "not")]);
    let locked = kept.path().join("locked.md");
    std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o000)).expect("lock the file");
    let changes = pending_changes(&vault).expect("the queue survives the unreadable file");
    std::fs::set_permissions(&locked, std::fs::Permissions::from_mode(0o644)).expect("unlock");
    assert_eq!(paths(&changes), [("good.md", ChangeKind::Added)], "the unreadable file is left out");
}

#[test]
fn the_command_answers_the_same_list() {
    let (vault, kept) = vault("command");
    seed(kept.path(), &[("new.md", "added here"), ("edited.md", "changed now")]);
    recorded(&vault, &[("edited.md", "was like this")]);
    drop(vault); // the lock: the session needs it
    let mut registry = Registry::new();
    register_core(&mut registry).expect("register the core commands");
    let mut session = Session::open(kept.path()).expect("open the vault");

    let answer = registry.run("sync.pending", &mut session, &Value::Null).expect("the command runs");
    assert_eq!(
        answer,
        json!({
            "changes": [
                { "path": "edited.md", "kind": "edited", "size": "changed now".len() as u64 },
                { "path": "new.md", "kind": "added", "size": "added here".len() as u64 },
            ]
        }),
        "the same list the function returns, as JSON"
    );
}